Topics represent predefined queries associated with a data source with which ad hoc reports are created. Topics are typically created through Jaspersoft Studio by an administrator and deployed to the server for end-user convenience. Topics are also created from a Domain as an intermediate step during ad hoc report creation.
Creating a Topic in Jaspersoft Studio is similar to creating a report. Create a report with a query and optionally filters, deploy it to the Topics folder on the server, and associate it with a data source. Users can then leverage this predefined query to create their next ad hoc report.
For additional information see:
JasperReports Server User Guide: Creating Topics
JasperReports Server User Guide: Creating Topics from Domains